Sheet metal grain storage bins are used for both short-term and long-term storage of a wide variety of different grains. A grain storage bin of this type ordinarily includes a sheet metal housing, an elevated perforate sheet metal floor, and a fan for blowing air into the space below the floor so that the air flows upwardly through the floor and into the grain. The floor is made up of a plurality of elongated perforated floor members of generally channel-like cross-sectional configuration which interlock with each other to form a continuous floor. The floor may be supported on a variety of different kinds of support members; usually, the support members are freestanding sheet metal support legs. Examples of grain bin flooring systems of this general kind are disclosed in Kennedy U.S. Pat. No. 4,073,110 issued Feb. 14, 1978 and Trumper U.S. Pat. No. 4,137,682 issued Feb. 6, 1979.
The structural and operational characteristics of a grain bin floor can be relatively critical. To begin with, the floor must be quite strong, since the loading on the floor, when the grain storage bin is filled, may easily exceed one thousand pounds per square foot. Furthermore, the floor must support workers and their equipment during installation and cleaning. The perforations required in the floor, for passage of air, should be free of projections, since such projections can interfere with cleaning of the grain bin. Furthermore, any sharp projections on the top surface of the floor can present a severe problem to workers during installation of the floor, when it is frequently necessary to kneel on the floor while installing additional floor sections.
A grain bin floor construction previously manufactured and sold by Bantam Systems, Inc. of Chicago, Ill. and shown in that company's bulletin BS-2785 has afforded appreciable advantages as compared with the floor structures of the aforementiond Kennedy and Trumper patents. In the Bantam floor system, the individual floor members are arched transversely of the channel configuration and are also formed with a series of transverse corrugations, adding materially to the strength of the floor. The Bantam floor system employs multiple punched apertures for the ventilation openings, providing a high level of ventilation without sharp edges on the top of the floor that might interfere with cleaning or with installation. On the other hand, the multi-perforate construction used in the Bantam floor system is relatively costly, and the perforations weaken the floor somewhat due to the total amount of metal cut away, partially offsetting the improved strength characteristics provided by the arched and corrugated configuration of the floor members.